Steam boiler



April 1939- J. H. RGHRER 2,153,592

STEAM BOILE? Filed Dec. 5, 1955. 3 Sheets-Sheet 1 if z;

ATTdRNEY April 11, 1939. J H ROHRER 2,153,592

' STEAM BOILER Filed Dec. 3, 1935 3 Sheets-Sheet s M I W ATTORNEY Patented Apr. 11, 1939 UNITED STATES PATENT OFFICE 8 Claims.

This invention relates to steam boilers.

With the increase of power demands in industry and the necessity for the faster production of steam, boilers have been built of increasing size and volume. The efforts in the past, however, have been to merely increase size without disturbing the conventional internal arrangements or designs, with a consequent loss of emciency and with an unnecessarily high cost. Thus, in most recent large boiler installations with which I am familiar, for instance, the conventional headers have been used, with fluid-containing pipes of such length and number of bends as to militate against easy cleaning.

It is among the objects of this invention; to improve the art of steam boilers generally; to obviate the use of headers in steam boilers; to improve the efliciency of boilers; to prevent the exposure of bare walls to the heat of the flame in the boiler; to provide an improved circulatory path for the flames and heated gases in steam boilers; to increase the efficiency of heat transfer between heated gas and the fluid-containing pipes to be heated; to provide a curvilinear path for hot gases intersecting fluid-containing pipes to secure transfer of heat into the fluid in the pipes by both convection and reflection or radiation; and many other objects and advantages as will become more apparent as the description proceeds.

In the accompanying drawings forming part of this description:

Fig. 1 represents an elevation, partially in section, through a boiler incorporating some of the features of this invention,

Fig. 2 represents a vertical section through substantially one half of the boiler of this invention taken on line 22 of Fig. 1,

Fig. 3 represents a vertical section through substantially one half of the boiler of this invention taken on line 3-3 of Fig. 1, and being through the opposite boiler half from the section of Fig. 2,

Fig. 4 represents a fragmentary horizontal section through the half boiler of Fig. 3,

Fig. 5 represents a fragmentary enlarged elevation of a detail of the pipe and baffle assembly.

The boiler of this invention comprises a large compartment having generally conventional insulated walls, and comprises with other walls, to be described, the rear wall II], in which is the opening II for the burner for the boiler, which may be of any desired sort, and forms of itself no part of this invention. The burner will usually be one which uses either pulverized coal or other fuel, or which uses a fluid fuel, such as either gas or oil or the like. For the present it will be suflicient to note that the flame in the boiler is projected forwardly toward the front wall I2, as well as laterally toward the side walls I3 and I4, from the rear wall Ill. At the bottom of the boiler a pair of spaced longitudinal curbs or girders I 5 and I6 are provided, and the bottom comprises a connecting flooring IT. The curbs I5 and I6 and associated wall elements are arranged to support the drums to be described, running longitudinally of the boiler between the front wall I2 and rear wall Ill. At the top the compartment has the transverse wall sections I3 and 2B, merging in the longitudinal domed supercharging head 2!, to be further described. The outer walls are provided with any desired number of inspecting and cleaning doors and the like, as 22, which form no particular part of the invention herein.

By reference to Fig. 4, it will be observed that the front and rear walls, respectively It! and I2, have been modified from the conventional in their relations to each other and to the side walls I3 and I4. Rear wall II] is provided with inwardly stepped areas, as 23, and 24, which are successively nearer to the front wall than the main body of the rear wall II). The same is true of the front wall I2, which has inwardly stepped areas 25 and 26, which have therefore effectively shortened the side walls I3 and I4, so far as the inner dimensions of said side walls are concerned. It will be understood that the inward step of rear wall ID, to stepped area 23, is by means of riser or angle portions 21', usually parallel with side wall I3, while area 23 is spaced from area 24 by a similar riser 28 or short perpendicular wall. Similarly the steps in the front wall are connected by riser portions respectively 36 and 3I. Obviously this facilitates the construction to be described, but is not essential, as the front and rear walls could each be simply tapered off to get the same general effect, as will be further mentioned.

Adjacent to side wall l3, suitably supported on the curb I6, is the longitudinally extending drum 32. A similar complemental drum 33 is supported on curb I5 adjacent to side wall I4, and each drum extends, as shown in Figs. 1 and 4, the full length of the boiler and even beyond the outermost plane of the rear wall I0 and front wall I2, if desired, and, at least at one end, each drum is provided with a man-hole closure or clean-out 34.

Within the dome 2|, an enlarged steam drum 35 is mounted projecting longitudinally of the boiler and provided at one end with a suitable water level indicator, as 35, and at the other with a suitable man-hole cover or closure 31, and with suitable safety valves, and the like as 38. The upper drum 35 is provided with a vertical baffle wall 4|] extending from the bottom opening 39 thereof, to spaced relation to the top of the drum a little past the center toward the front wall where it merges into the flattened V-shaped horizontal steam bafile 4|, in turn merging into the vertical arcuate bafile 42, close to the line of the rear wall Ill. The baffle assembly just described is to prevent splashing of water into the steam superheating pipes to be described, while permitting longitudinal water and steam movement.

It is to be understood that for general purposes the boiler is symmetrical about its longitudinal axis and a description of one side should suffice for both. In considering Fig. 1 it is to be remembered that although each half of the boiler is opposed by a similar complemental construction, yet the halves are not symmetrical relative to a transverse axis, as shown by the differences observable of Figs. 2 and 3. In Fig. 3 the right hand side of the boiler is shown and represents a section through a portion of the boiler, closer to the rear wall thereof, and of course represents what the complemental half of the boiler would resemble at that section line 3-3. Fig. 2, as noted, shows the left hand side of the boiler of Fig. 1, through a different portion of the boiler, closer to the front wall thereof, and obviously represents what the complemental half of the boiler would resemble at that section line 2-2.

In order to provide a restricted channel 53 for hot gases on each side of the boiler, there are provided at intervals on the sides of respective drums 32 and 33, toward the upper parts thereof, in relations staggered both arcuately and longitudinally of the drums, a plurality of pipes, respectively 41 emerging from the drums toward but spaced from the top thereof, and pipes 48 emerging from the drums further down from the top. Pipes 4'! and 48 are in spaced relation at their lower and upper ends, but are bent to contiguous relation to form practically solid walls of pipes 52 each disposed in a substantial plane extending longitudinally the entire length of the boiler between the stepped areas or portions 24 and 23 of walls H3 and E2, in parallelism with both side walls l3 and 14. Each wall 52 includes connecting bafiies 53, which close off all spaces between pipes 41 and 48, and extends the entire longitudinal extent of pipe walls 52, at the bottom adjacent to the drums 32 and 33, and also extends vertically from gas tight relation to drums 32 and 33 in approximately one half of the longitudinal extent of the wall 52, to contact with steam drum 35, shutting off all space between the upper ends of pipes 41 and 48. Walls 52 at the rear of the boiler, on each side, terminate at point 5|, at the beginning of separation of pipes 41 and 48 at the top of their respective vertical extents, in spaced relation to the top of wall element 23, to form a channel mouth or entrance 54 for hot gases to enter into channel 53 in which mouth and channel the banks of pipes to be described are disposed. There are' such mouths 54 on each side of the boiler toward the rear portions of walls 52.

It is a feature of interest that the gas channels 53 disposed between the banks of pipes and baffles 52 and the respective side walls i3 and i4, and, in the front halves, additionally between the baflies 53 and pipes 47 and 48 and the upper transverse walls I8 and 20, are each divided vertically into separated ducts by a transverse vertical wall 49'. The dividing walls extend from a lower edge 55, about at, or slightly above, the lower separation point between pipes 41 and 48, vertically in lateral sealed engagement with pipe wall 52, and the respective side walls l3 and i4, respective top walls It and 2D, to sealed abutment against the lower surface of upper steam drum 35. Obviously the vertical baffles form one wall of the hot gas inlet or mouths 54 and of a down draft duct of which the opposite wall is rear wall It) and its inwardly stepped areas. An up draft duct is defined between dividing wall 43 and front wall 12 between pipe walls 52 and side walls l3 and I4.

The boiler is provided with stack openings 53 in the fore part, communicating with the gas channels 53 forward of the median baffles 49 and the arrangement is obviously such that the flames and hot gases rising on all sides of the boiler give up large amounts of heat to the pipes comprising the walls 52, and large amounts also to the pipes, to be described, which line the front and rear walls, and finding no outlet at the front end, are caused to divide and enter the opposed rearwardly disposed mouths 54 into the down draft side or duct of the channel, across the lower edge 55 of the median wall in a flow longitudinal of the boiler, then upwardly through the up draft side or duct of the channel, and out. through the stack openings 59.

It will be observed that a longitudinally spaced series of laterally spaced pipes is provided in each channel or passage 53, in each series of which one pipe, as 43, rising from communicating engagement with the drum 32, is housed or disposed more or less insulatedly within part of the fire brick or other insulation of the side walls 13 and I4, and forms the return circulation for more or less cool water. In addition to the concealed and housed pipe 43, there is in each series, three other pipes, respectively 44, 45 and 46, arising substantially vertically out of the upper part of drum 32, and all extending vertically, in a substantial plane, parallel, generally to either front or rear wall, for practically the entire height of the walls l3 and I4, curving at their upper ends, into anchored communicating relation to the enlarged or upper drum 35, as shown.

It will be clear that with the distribution of pipes arising from the drums 32 and 33 as described, all forming either the wall of pipes comprising the flue or gas channel boundary or the bank of pipes within the channel, there would according to prior practice be no protection for either of the end walls of the boiler, which, being subjected to the devastating heat of the flame, would require constant repair to replace the burned brick or other surfaces. It is an important feature of this invention that this widesirable possibility is removed, with an increase in eificiency of the whole boiler.

. It will be observed in Fig. 3 that the recessed steps, or inwardly disposed wall areas 24 and 23 are built directly transversely of or normal to the drum 32, extending clear across it, well inside of the ends thereof, and that these inwardly stepped wall areas 24 and 25 form with the side walls l3 and i4 and pipe walls 52 an enclosed gas channel, which is filled with a bank of pipes emerging from the drum between the recessed end wall areas. It will be observed that there is considerable longitudinal extent of drum 32 (and also of drum 33) extending outwardly of the end wall areas 24 and 26. It is preferred to provide secondary series of steam pipes, respectively, 56, 51, 58, 60, 5% and 62 emerging out of the side and top of respective drums 32 and 33, beyond respective wall areas 2 2 and 23 which pass laterally through the risers 28 and 3|, to lie in spaced relation in front of and in contact with, the insulating stepped wall areas or panels 23 and 25 of the front and rear walls l2 and it! respectively. Similarly a further secondary series of pipes 63, 64, 55, 55, 57 and 53 emerge out of the top and side of the drum 32, adjacent its ends, obviously further beyond end wall panels 24 and 26 than the first recited bank of pipes 56, 51, 58, 56, GI and 52, and pass laterally through the risers, 36 and 21 to overlie the front and rear wall areas l2 and it respectively. If the boiler has appreciable front and rear wall area, still other panels and protecting layers of pipes may be provided, as will be clear. It will be understood that the junction of pipes 55, 51, 58, 60, 6| and 62, and 63, 64, 55, 56, 51 and 68 with drums 32 and 33, will be suitably protected with desired sorts of insulation, but that after passing through the respective riser structures they are disposed in the furnace for the impingement of hot gases. These auxiliary end panel pipe series 55, 51, 58, 60, BI and 52, and 83, 64, 55, 53, El and 58 rise vertically and enter ccmmunicatingly into engagement with the large drum 35. It will be observed that the entire front and rear walls are covered by the slightly spaced end wall protecting pipes. It will further be observed that with a boiler using drums and not headers, the entire combustion space except for the floor is lined and covered with steam pipes, on all four sides and the top. This obviously makes for a most efficient utilization of all of the available heat while interfering with the destructive processes that follow impingement of flames on bare walls.

It has been the case in the past that the hot gases move in directions generally parallel to the steam pipes, and heat transfer has been by con vection only. I have discovered that the positioning of a plate in substantial parallelism with and between the pipes materially increases the heat absorption of the pipes, as the energy directly absorbed by convection is enhanced by the additional energy absorbed through reflection and radiation from such plate. While such substantially flat plate positioned as described is of value and is part of this invention, yet the further modification of the principle shown inFig. 5 is generally preferred. As shown in Fig. 5, and also in Fig. 1, adjacent longitudinally spaced series of steam pipes in channels 53, are separated from each other by the generally vertically corrugated generally vertically extending reflecting, radiating and guiding metallic sheets 70. With the corrugations in transverse alignment or registration, it will be observed that a pair of plates or sheets define a circuitous passage H, within which is a row of laterally aligned steam pipes, and relative to which ascending (or descending) gases have a movement as indicated in the long arrows of Fig. 5, to secure greater convective heat transfer, through intimacy of contact, and also, through radiation from each side of plates Hi, as shown in the small arrows, the total heat transferred to the pipes is increased. If plates 10 are actually in physical contact with pipes M, etc., which is not essential to secure the primary benefits of the invention, there may exist still a further enhancement of energy absorption through conduction from plate '10 into pipe 44.

It being desirable to superheat the steam developed, the bank of pipes in the mouth 54 of channel 53 may contain a series of superheating coils or conduits 12, each of which leads from a point above the horizontal or splash bafiie 4| in upper steam drum 35 at 13, in dome 2i, thence down to coiled position in the down-draft duct of channel 53, to a point above edge 55 of dividing wall 49. This spacing is so as to leave room for short corrugated reflecting bailles M. The coils are reversed and return to the upper part of the bank of pipes, then downward again and again reversed and then lead upward to discharge into the super-heated chest or drum (5, at the top of dome 2|.

The advantages of the invention, and the many modifications that may be made therein will be obvious to those skilled in the art. Thus it will be clear that any other sort of wall construction desired may be used to secure positioning of steam pipes against the end walls of the boiler to protect the wall material and increase the efiiciency of the boiler. All such changes are to be construed as within the scope of my invention unless otherwise limited in the following claims.

I claim:

1. In steam boilers, means defining a combustion chamber having walls, a drum on each side of the chamber, a single upper drum, pipes connected to the side drum and forming a longitudinal wall of the combustion chamber, supplemental pipes connected to each side drum in a plurality of rows in front of a transverse wall of chamber, each row and its connection to the drum lying substantially in a plane perpendicular of the drum. the respective rows and planes being spaced longitudinally of the chamber.

2. In steam boilers, a pair of parallel spaced drums, a wall panel substantially perpendicular to and intersecting a drum, a row of pipes extending substantially vertically in front of said panel in position to protect same from hot gases, and communicatingly engaging one of said drums, a second wall panel and a second row of pipes communicatingly engaging one of said drums beyond the intersection of the first panel and extending substantially vertically in front of said second panel to protect same from hot gases.

3. In steam boilers a rear wall and a side wall, a drum extending substantially parallel to said side wall and extending through the rear wall, a pipe communicatingly engaging said drum inside of said rear wall and bent laterally to a position in front of said rear wall in close proximity thereto, and a second pipe engaging said drum outside of said rear wall and bent to a position inside of said rear Wall in front of said rear wall in close proximity thereto.

4. In steam boilers, a rear wall and a side wall, a lower drum substantially parallel to the side wall, an upper drum substantially parallel to the first mentioned drum having an axis which intersects the rear wall spaced from the side wall, a bank of pipes rising vertically from the lower drum and bent to communicating engagement with the upper drum while exposing an area of the rear Wall, a plurality of spaced pipes engaging c-ommunicatingly said lower drum and being bent to rise substantially vertically substantially in a plane substantially perpendicular to the lower drum and parallel to the exposed area of the rear wall in such proximity thereto as to shield same from incident flames, a secondary plurality of spaced pipes engaging communicatingly said lower drum and being bent to rise substantially vertically substantially in a plane substantially perpendicular to the lower drum in longitudinally spaced relation to the average plane of the first mentioned plurality of pipes, the second mentioned rising portion being disposed laterally of the first mentioned plurality of pipes so as to shield another area of said rear wall from incident flames, and a wall forming row of pipes extending from the lower drum in spaced substantially parallel relation to the side wall and into the upper drum to form with the side wall a gas passage containing said bank of pipes.

5. In steam boilers a compartment comprising a rear wall, a side wall joining the rear wall, a drum substantially parallel to the side wall intersecting and having a portion extending beyond the rear wall, a bank of pipes emerging from the drum inwardly of the rear wall within the compartment, a series of pipes emerging from the extended portion of the drum having portions disposed spacedly inwardly of and adjacent to the rear wall within the compartment.

6. A steam boiler comprising front and rear walls and side walls, said side walls being longitudinally shorter than the major distance between front and rear walls, a drum extending between the front and rear walls adjacent a side Wall of a length substantially the same as the said major distance between front and rear walls, a bank of pipes rising from said drum adjacent the side walls, an auxiliary series of pipes rising from said drum to overlie the respective front and rear walls in laterally spaced relation to said bank of pipes and a supplemental auxiliary series of pipes rising from said drum beyond the front and rear walls to overlie the respective front and rear walls in laterally spaced relation to the first mentioned auxiliary series.

'7. A steam boiler having a non-planar front wall, a side wall joining part of said wall, a drum intersecting said front wall, a bank of pipes emerging from the drum, a guarding series of pipes overlying the front wall laterally of said bank and emerging from said drum beyond said front wall.

8. In steam boilers a walled compartment having a pair of parallel spaced lower drums ex tending longitudinally of the compartment, and a single upper drum extending longitudinally of the compartment, a plurality of rows of pipes communicating with the respective lower drums and extending vertically and. bent to communicating engagement with the upper drum, a plurality of pipes communicatingly engaging the respective lower and upper drums and disposed in alignment longitudinally of the compartment to form a pipe wall extending the full length of the compartment substantially parallel to each side wall of the compartment for an appreciable vertical extent, all of said pipes and upper drum forming the only communication between the lower drums, baffle means connecting the adjacent pipes of the pipe wall to render same substantially gas-tight for the entire vertical length of the pipe wall in one portion of the compartment, and being removed for forming a flame inlet at the upper portion of the pipe wall, and partition means extending from the upper drum downwardly adjacent to the open mouth of the pipe wall, toward the respective lower drums about the lower edge of which hot gases pass in the circulation of the products of combustion in said boiler about and past said first mentioned rows of pipes.

JOSIAH H. ROI-IRER. 

